KR100667994B1 - Apparatus for adjusting the tension of the wound part of a belt drive transmission - Google Patents

Abstract

The invention proceeds from a system for adjusting the tension of a belt part (for example, a band) of a belt transmission mounted downstream of a vehicle engine. The belt transmission preferably is continuously adjustable with respect to its transmission ratio. A first means is provided for controlling (open loop and/or closed loop) the vehicle engine and a second means is provided for controlling (open loop and/or closed loop) the belt transmission. Here, a first signal is determined by the first means and this signal represents the engine torque of the vehicle engine and this signal is supplied by the first means to the second means. The tension is adjusted by the second means in dependence upon the first signal and a safety reserve. The essence of the invention is that the safety reserve is not fixedly pregiven; instead, it is determined in dependence upon various conditions. In this way, one achieves a reduction of the reserve pressure of the belt tensioning control and thereby reaches a better operating efficiency of the transmission and therefore a reduced fuel consumption.

Description

A device for adjusting the belt tension of a continuously variable transmission {APPARATUS FOR ADJUSTING THE TENSION OF THE WOUND PART OF A BELT DRIVE TRANSMISSION}

The present invention relates to a device for adjusting the belt tension of a continuously variable transmission according to the preamble of claim 1.

Such a device, for example disclosed in EP 0 451 887, is described in FIG. The publication relates to tension adjustment of the belt 1 in a continuously variable transmission 2, which consists of a belt 1, a drive pulley 3 and an output pulley 4.

In order to adjust the speed ratio of the continuously variable transmission, and to adjust the tension of the belt 1, the drive pulley 3 and the output pulley 4 are axial fixed cone plates 7 and 8 and axial movable cone plate 9, respectively. , 10). The drive pulley 3 is also referred to as primary pulley, and the output pulley 4 is also referred to as secondary pulley. The hydraulic pressure is formed in the oil chambers 5, 6 so that the axially movable cone plates 9, 10 push the belt 1. By appropriately selecting the pushing pressures P _prim, P _sek in the oil chambers 5, 6, the desired transmission ratio and the required tension of the belt 1 in the continuously variable transmission can be adjusted. In order to transfer power from the engine 11 to the drive pulley 3, for example, a torque converter 12 and a planetary gear 13 device comprising a forward clutch and a reverse clutch can be provided. . The engine 11 may drive the pump 14 of the continuously variable transmission. The transmission control device 18 includes an electric element and a hydraulic element for controlling the continuously variable transmission. The transmission control device 18 comprises means for adjusting the pressure of the oil chamber 6 or the oil chambers 5, 6.

The tension of the belt 1 is adjusted by the pressure P _sek of the output side oil chamber 6 by the operation of the transmission control device 18.

The tension of the belt 1 is adjusted to maximize the efficiency of the continuously variable transmission. At this time, on the one hand, the tension of the belt 1 is too small to prevent the belt from slipping, and on the other hand, the tension of the belt 1 is prevented from becoming too large to suppress a large loss in the continuously variable transmission. Should be. In order to match both conditions, the torque transmitted from the drive pulley 3 to the output pulley 4 should be known as accurately as possible. At this time, the torque to be transmitted from the drive pulley 3 is mainly determined by the torque increase ratio of the engine 11 torque and the torque converter 12.

EP 0 451 887 discloses a method for adjusting the pressure P _sek of the output side oil chamber 6. In this method, the opening angle α _Dk of the throttle valve 15 of the engine 11 is detected by the sensor 16. In addition, the speed N _mot of the engine 11, the speed N _prim of the drive pulley 3, and the speed N _sek of the output pulley 4 are measured by the speed sensors 19, 20, 21. It is provided to the transmission control device 18 as a suitable signal. Each position α _Dk of the throttle valve, the engine speed N _mot , the drive pulley speed N _prim and the output pulley speed N _sek measured by the sensor 16 are determined by the oil in the transmission control device 18. It is used to adjust the tension of the belt 1 by adjusting the pressure of the chamber 6.

In order to adjust the tension of the belt 1, the expected engine torque is calculated using a characteristic curve consisting of the throttle valve angle and the engine speed. The expected engine torque is formed from the drive pulley speed value and the engine speed value in the characteristic curve and converted into the expected primary torque. After that, the necessary pressure P _sek is calculated in the output side oil chamber to adjust the tension of the belt 1.

The disadvantage of using the throttle valve angle α _Dk to calculate engine torque is that the throttle valve potentiometer must be adjusted very accurately. Small deviations between the measured throttle valve angle and the actual throttle valve angle may cause a significant deviation between the expected engine torque and the actual engine torque in the method. Since it is difficult to ensure that the throttle valve angle can always be measured accurately, a pressure greater than the reserve pressure must be adjusted in the output oil chamber in order for the belt tension to be kept above the required level with a larger safety reserve. This causes greater losses in the transmission and the pump. Furthermore, problems arise in the calculation of engine torque during dynamic driving states where the change in engine speed over time is greater.

In the case of German Patent No. 195 48 722, the above-mentioned adjustment of the belt tension is improved by, for example, the torque value calculated in the engine control apparatus being used for the adjustment of the belt tension. However, embodiments for the detection of the safety reserve are not disclosed herein.

In today's engine control systems, misfire detection is usually used in one or more cylinders of an automobile engine, at which time engine unstable operating values are calculated from fluctuations in engine speed. The value is compared with the threshold applied. If the engine instability operating value exceeds a threshold, misfire is detected. It is mentioned in German patent 41 38 765. Many obstacles in engine speed are causing problems. Such disturbance variables are, for example, mechanical failures of wheel-type transmitters at engine speed detection, charge differences (different from combustion processes) and torsional vibrations of individual cylinders. In order to accurately detect misfire, the fault generating element is adapted in normal operation, which is disclosed in German Patent No. 196 22 448 and European Patent No. 0 733 890. In other words, a correction value considered for accurate detection of engine speed is used after the adaptation.

In addition, in the prior art, for example, in the magazine mot No. 15, November 6, 1998, an inter-vehicle distance control system for detecting the inter-vehicle distance with the front car is known. This is usually done through radar sensors. If the distance is too narrow, the system will provide braking interference separately from the driver.

It is an object of the present invention to optimize belt tension, specifically the detection of safety reserves.

This object is achieved through the features of claim 1.

As mentioned above, the present invention provides a first means for controlling the automobile engine and a second means for controlling the continuously variable transmission, in order to adjust the tension of the belt of the transmission installed downstream of the automobile engine. And a first signal indicative of the engine torque of the automobile engine is detected through the first means, the first signal is provided from the first means to the second means, and the tension is transmitted to the first signal and the safety reserve through the second means. To the device being adjusted accordingly.
The key point of the present invention is that the safety reserve is not fixed and preset, but is determined by various conditions. This reduces the overall reserve pressure of the band tension adjustment, resulting in better transmission efficiency and thus lower fuel consumption.

In a first embodiment of the invention a second signal representing the quality of the first signal is detected via the first means. Then, as soon as the second signal is provided from the first means to the second means, the safety reserve is detected according to the second signal. The belt or band is thus protected from excessive wear in situations where engine torque is incorrect.

In a second embodiment of the present invention, means are provided for detecting an aging value indicating wear or aging of the belt. Thereafter, the safety reserve is detected in accordance with the aging value. In this embodiment, it is contemplated that the pushing pressure required for slip prevention is highly dependent on the wear or aging of the belt. That is, new belts for transmitting the same engine torque require less pushing pressure than already worn or worn belts. The present invention allows the belt tension to be properly adjusted to the state of the belt.

In a third embodiment of the present invention, a third means is provided, wherein a third signal indicative of braking performance adjusted at the wheel or yawing or transverse motion of the vehicle is detected using said third means. Thereafter, the third signal is provided from the third means to the second means, and the safety reserve is detected according to the third signal. The advantage of this configuration is that a sudden torque change on the transmission output side is detected. For that reason, timely increase in belt tension can be considered.

In a fourth embodiment of the present invention, a fourth signal is provided to the second means indicating the speed or the change of the speed of the at least one wheel. Thereafter, the safety reserve is detected according to the fourth signal. As in the third embodiment, the background of this configuration is that a sudden torque change on the transmission output side can be deduced from the dynamics of the wheel. If the wheel dynamics exhibits such a torque change, it is advantageous that an increase in belt tension can be considered in a timely manner.

In a fifth embodiment of the present invention, a fourth means is provided for the above-mentioned inter-vehicle distance control, wherein the means is adapted to cause an interference signal to the braking device of the vehicle or to provide an interference signal depending on the distance to the preceding vehicle. Detect. According to the invention the safety reserve is detected according to the interference signal. Since a sudden torque change or torque coupling on the transmission output side may also be caused in the transmission even through braking interference for controlling the inter-vehicle distance, it is desirable to consider the torque change when detecting belt tension.

In a sixth embodiment of the present invention, a fifth means is provided, said means for detecting by way of at least one sensor a road value indicative of a ballistic trajectory of the road through which the vehicle will pass. The sensor may be a radar sensor that outputs an output signal that is also used to control the aforementioned inter-vehicle distance. The safety reserve is detected according to the road value. The configuration is based on the fact that sudden torque changes can occur at the transmission output and at the belt even due to uncompromised roads. In this case the belt tension is correspondingly increased to prevent damage to the belt.

In the first configuration, the second signal indicates the degree of oscillation of the first signal, that is, at least the engine torque, as a quality.

At this time it is conceivable that the second signal is preferably detected in accordance with the tolerance of at least one sensor which outputs an output signal which is evaluated for control of the automobile engine, i.e., the characteristic of the engine torque. in this case

The sensor is used for direct or indirect detection of the amount of air supplied to an automobile engine,

The sensor is used to detect a temperature which is evaluated for control of the vehicle engine,

The sensor outputs an output signal which is used for the detection of the fuel-air-mixer supplied to the automobile engine and is used for detecting the exhaust characteristics of the automobile engine.

The sensor for directly or indirectly detecting the amount of air supplied to the vehicle engine may be configured, for example, as a hot film air flow meter, as an intake pressure sensor, or as a throttle valve potentiometer for measuring each position of the throttle valve.

In another advantageous variant of the first configuration the second signal is detected in accordance with a malfunction detected during operation of the motor vehicle engine. In this case the malfunction is

If misfire is detected in one cylinder or multiple cylinders of an automobile engine, through evaluation of the detected engine speed, or

A malfunction of a sensor outputting an output signal that is evaluated for control of the vehicle engine is detected, or

-If there is an electrical emergency in the first means, or

If the fuel supply to the individual cylinders of the vehicle engine is interrupted in response to error detection.

In a further advantageous variant of the first configuration the second signal is detected in accordance with the detected unstable operation of the motor vehicle engine. In this case, detection of unstable motion

Mechanical vibrations, in particular torsional vibrations, are present in the drive train of the vehicle, or

The fuel supply to the individual cylinders of the car engine is interrupted, or

The first means controls the vehicle engine to suppress vibrations in the drive train (antijerking function, load shock absorption), or

Whether a switchover is made between different modes of operation of the car engine, or

Whether the presence of the set road quality is detected (road detection)

It depends on whether the fuel tank is almost empty.

Switching between the various modes of operation of an automobile engine is, for example, a switch between homogeneous and stratified air supply of an engine for a gasoline direct injection engine.

At this time, the second signal is detected according to a stored adaptation value representing an unstable operation of the engine, and the adaptation value may be stored according to a load or a speed.

In the last advantageous variant of the first embodiment, the second signal is detected according to the inaccuracy which appears upon detection of the first signal. in this case                 

A second signal is detected according to the speed of the car engine, or

Adaptation of the frictional or lost torque during idling of the motor vehicle engine via the first means and a second signal is detected depending on whether the adaptation has ended.

In the second configuration, the aging value is detected in accordance with the operation period of the belt. In this case, the aging value is detected according to the operating conditions during the operation period such as the driving behavior of the driver, the operating temperature or the slip of the belt.

At this time, the aging value is detected by the second means and stored non-volatile there.

In a fourth configuration a fourth signal is provided from the third means to the second means and the third means is as an anti-blocking system (ABS) or as a drive slip control system (ASR). Or as a driving stability control system (ESP) used to adjust the braking torque acting on the wheels to increase driving stability.

In a sixth configuration at least one clutch is provided in the drive train of the vehicle, which clutch is opened according to the road value and the detected error type, in particular a misfire. This may be a torque converter lockup clutch directly connecting the torque converter provided to the drive train. Such opening of the converter clutch may also be advantageous in misfire detection described in the first configuration.

According to the invention the safety reserve is preferably detected as follows:

In the first configuration, the tension of the belt becomes greater if a lower quality first signal is presented compared to the adjusted tension when a high quality first signal is presented.

In the second configuration, the tension of the belt becomes greater if the aging or wear is greater than the adjusted tension when less aging or wear is presented.

In the third configuration, the tension of the belt becomes greater if the yawing or lateral motion or braking performance is greater than the adjusted tension when the yawing or lateral motion or braking performance is presented small.

In a fourth configuration, the tension of the belt becomes greater if the speed or speed change of the at least one wheel is presented large compared to the adjusted tension when the speed or speed change is presented small.

In the fifth configuration, the tension of the belt becomes large when there is braking interference caused through the fourth means.

In the sixth configuration, the tension of the belt becomes greater if the road incompatibility is presented larger than the adjusted tension when the road inaccuracy is presented small.

A particular advantage is that the tension value according to the first signal, ie according to the engine torque, is detected. In that case the base value is modified or increased in accordance with the safety reserve. In this case the tension adjustment is hydraulic and the tension is adjusted via a setpoint of at least one pressure value. A pressure value (base value) is detected in accordance with the first signal, and this pressure value is corrected or increased in accordance with the safety reserve.

Another advantageous configuration of the invention is identified in the dependent claims.

1 and 2 are block diagrams of the prior art.

3 is a block diagram illustrating the basic elements of the present invention.                 

4, 5, 6, 7, 8 and 10 are block diagrams illustrating in detail the embodiment according to the present invention.

9 is a graph showing the curve of belt tension correlated with engine torque.

11 is a diagram illustrating road flatness detection.

12 is a flowchart of the embodiment.

The invention is illustrated using several examples below.

For this purpose, FIG. 2 is first shown as a block diagram, and blocks already described with reference to FIG. 1 are provided with the same reference numerals.

2 shows a continuously variable transmission comprising a transmission control device 18 connected to an engine control device 22 controlling an internal combustion engine 11 via a data line 23. One or more signals may be transmitted from the engine control device 22 to the transmission control device 18 via the data line 23. In the drawings, the engine torque M _mot and the characteristic ΔM _mot , which are important to the present invention, or the degree of swing of the engine torque can be regarded as data.

In order to control the engine 11, the engine control device 22 receives various signals about the operating state of the engine by the lines 116, 119, 123, 124, and 126. Actuator of engine 11 is controlled by lines 125 and 130.

2, the braking control unit and the vehicle distance control unit are indicated by reference numerals 101 and 102. In FIG.

At this time, the brake control unit 101 is generally configured as a blocking prevention device, a drive slip control device or a travel stability control device. The devices control the brake so that blocking or spin of the wheel is avoided or driving stability is improved. The braking torque M actually acting on the wheel generally in the brake control unit 101 ), Yaw rate (ω ') or lateral acceleration acting on the vehicle, wheel acceleration (a_rad) Or wheel speed (N_rad) Is provided. The values are provided to the transmission control device 18 individually or in combination.

The inter-vehicle distance control unit 102 detects the distance between the obstacle and the vehicle or the inter-vehicle distance between the vehicle ahead. Depending on the distance, that is, interference with the automobile brake can be actively made to increase the distance. The interference is indicated by the signal ACC provided to the transmission control unit 18. In addition, the road condition FB may be detected through the inter-vehicle distance control unit 102 and provided to the transmission control device 18.

3 shows the flow of detection of signals 116, 119, 123, 124, 126 and control of the internal combustion engine 11 by signals 125, 130. One of the cylinders of the internal combustion engine 11 is shown. The speed N _mot signal 119 of the engine is measured by the speed sensor 19. The amount Q _L of air 26 sucked into the intake pipe 29 through the sensor (air flow meter) 24 is measured and provided to the engine control device 22 as a signal 124. The engine control device 22 operates the fuel allocation device with a signal 125. At this time, fuel is injected into the intake pipe 29, for example. The device 25 may for example be a fuel injection valve. Further, the control α _z of the spark plug 30 for ignition of the fuel-air-mixer in the combustion chamber 31 of the internal combustion engine 11 is composed of a signal 130 output to the engine control device 22. . The exhaust component is detected as the signal 123 through the lambda sensor 32 provided in the exhaust pipe. In addition, the engine or coolant temperature is measured using the temperature sensor 33 and provided to the engine control device 22 as a signal 126.

The engine control device 22 follows the signal 124 indicating the amount of air sucked into the internal combustion engine 11 and provides signals 125 and 130 for the control of the internal combustion engine 11. The speed N _mot of the internal combustion engine is provided as the signal 119 and the respective position α _Dk of the throttle valve of the engine control device 22 as the signal 116.

The engine control device 22 detects the expected engine output torque and transmits the result to the transmission control device 18 via the line 23 as a signal M _mot . Expected torques are calculated from signals 119 (N _mot ), 124 (sucked air Q _L ), 116 (α _Dk ), 125 (injection) and 130 (ignition time α _z ) Methods of making are known in the art. The detection of engine torque is described in engine control device 22, which includes block 221 in FIG. 4.

As shown in Fig. 8, the tension of the belt is set through the adjustment of the secondary pressure according to the engine output torque (signal M _mot ) expected or currently adjusted in the transmission control unit 18. This is done in block 181 of FIG. 8, through which the temporary target value P _{sek, unk} for the secondary pressure is first formed in accordance with M _mot . In addition, as described below, several values SR1 to SR6 are detected, and the values are summed into one safety reserve SR through the adder 188. The value SR is added to the target value P _{sek, unk} for the secondary pressure through the adder 189 to become the value P _{sek, kor} , and through the value, The belt tension that you actually want to adjust is predetermined. The detection of the safety reserve SR is important for the present invention.

The respective values for the detection of the safety reserve SR and for adjusting the tension of the belt 1 are described below:

1. Detection of safety reserve according to engine-side influence factors:

In this part, the key to the present invention is to calculate how reliable and accurate the engine output torque M _mot , which is generally detected at the engine control device 22, is. In such a case, the safety reserve SR is detected in accordance with the present invention in accordance with the "characteristic" (ΔM _mot ) of the engine torque. Since the transmission control device 18 adjusts the belt tension or the secondary pressure by using the signal ΔM _mot , the belt 1 does not slip within the belt torque range. This is shown in FIG. The transmission control device 18 provides lower and upper torque signals to adjust the belt tension from the "engine torque M _mot " signal and the "torque accuracy ΔM _mot " signal.

The reliability and accuracy of the expected or currently adjusted engine output torque (signal M _mot ) depends on the following factors:

Tolerance of the sensor outputting an output signal that is evaluated for control of the vehicle engine 11. The tolerance of the sensor is important at this time, and its output signal is used for the detection of engine torque M _mot . To this end, a value ΔTol is formed at block 222.

Malfunction of the car engine 11. For this purpose a value ΔFF is formed at block 224.

Unstable operation of the car engine 11. For this purpose, a value ΔLU is formed at block 223.

Inaccuracies in the detection of engine torque M _mot . This is considered through the value ΔTol formed at block 222.

As shown in the figure, the characteristic ΔM _mot of the engine torque is detected and provided to the transmission control device 18 in the addition unit 225 of the engine control device 22 in accordance with the elements ΔTol, ΔLU, ΔFF. . As will be explained below, the signal ΔM _mot contributes to the formation of the belt tension in the transmission control device 18, so that the larger the ΔM _mot , the greater the safety reserve against the belt tension.

1a) Sensor Tolerance and Inaccuracy (Block 222 / FIG. 4):

Determination of the engine torque M _mot (block 221 in FIG. 4) in the engine control device 22 is made under various tolerances and instability. The engine torque M _mot is for example calculated from the measured air quantity Q _L. However, the air flow meter 24 has a tolerance. In addition, the friction torque of the engine 11, for example in today's series of engine control systems, is adapted in the sense of learning, ie adapted at idle. This means that the adaptation of the friction or loss torque is made via the engine control device 22: this is done at idle of the automobile engine. However, the adaptation means that after installation of the new engine control device 22 the torque signal M _mot becomes more inaccurate once than after the adaptation.

Thus, for example, in the operation of the engine control apparatus, a flag may be provided that indicates whether the engine torque is correct or otherwise incorrect. But the information is too crude.

The problem is solved according to the invention by detecting at block 222 of the engine control device 22 a signal ΔTol indicating the characteristics of the engine torque M _mot under consideration of inaccuracies and tolerances.

Through the adder 225, the signal ΔTol is provided to the transmission control device 18 as a quality or " torque accuracy " (ΔM _mot ) to overlap another value to be described.

For example, the engine control device 22 may, at block 222, signal ΔTol and torque inaccuracies in an operating region where the engine torque M _mot is empirically inaccurate than in situations where the accuracy of the engine torque is greater. Choose large.

Further, the signal ΔTol may be large at the beginning of the friction torque adaptation already mentioned. After recognizing the end of the adaptation, the signal ΔM _mot decreases again.

Torque tolerance or inaccuracy (ΔTol) is a percentage indication error that depends on the operating point (e.g., through a tolerance when detecting inhaled air Q _L ) and an absolute error that does not depend on the operating point (e.g. For example, the already mentioned, unimplemented adaptation of the friction torque).

Respective values of tolerance and inaccuracy are calculated at block 222. To this end, the output signals of the most important sensor that output the output signal upon which M _mot is determined are provided to the block 222. Such sensors include an air flow meter 24, a lambda sensor 32, an engine speed sensor 19 and an engine temperature sensor 33 in FIG.

Memory 2221 is provided at block 222 to store data for determining absolute tolerances and relative tolerances and inaccuracies.

The transmission control device 18 adjusts the secondary pressure P _sek and the belt tension with the combined signal ΔM _mot , so that the belt 1 does not slip within the belt torque range. This is illustrated using Figure 9 already described.

By taking into account the sensor tolerances and inaccuracies described in section 1a), it is possible to protect the belt 1 from wear in situations where the engine torque M _mot is incorrect.

1b) Unstable operation of an automotive engine (block 223 / FIGS. 4 and 6)

In part 1b), how the unstable operation of the vehicle engine 11 is considered is described. As the unstable operation increases, a sudden torque change on the engine side (transmission input side) may occur. For this reason, the belt tension should be large in time.

As a possible cause of the increase in unstable behavior, the following is considered:

-Strong torsional vibration in the drive train of the car.

-Cylinder cutoff. At this time, part of the cylinder, for example half thereof, is cut off in an engine including a plurality of cylinders in the case of a constant operating mode for energy saving reasons.

Significant ignition angle change or injection time change (in diesel or gasoline direct injection), for example during interference for suppressing jerking in the drive train (anti-jerking interference, absorbing shock loads)

-Run with the fuel tank almost empty.

-Switch between different modes of operation of the car engine. Therefore, for example, in an engine of a gasoline direct injection method, it is known to switch between a so-called homogeneous operation and a stratified air supply operation method depending on the operating conditions.

-Driving on bad roads, i.e. poor road surfaces. In this description, unstable operation is regarded as a result of running in a bad section. Described in the next part of the present application is how the signal FB, which indicates the quality of the road, is detected by evaluating other values not directly related to the engine control device.

Detection of unstable motion is known, for example, from the prior art mentioned above and is practiced in modern engine control devices. In FIG. 4, a block 223 is contained in the engine control device 22, which is explained using FIG.

The engine speed N _mot provided to the block 223 is processed at block 2231 to become a signal indicating unstable operation. At block 2223 an appropriate algorithm is executed for this. A characteristic curve in which various values ΔLU are assigned to various unstable operating values dlut is stored in block 2232. As will be explained later, the value ΔLU contributes to forming the belt tension in the transmission control device 18 via the adder 225 in the sense that the belt tension becomes larger as the unstable operation becomes larger.

1c) Malfunction of the car engine (block 224 / FIGS. 4 and 5):

In part 1c), how the malfunction of the automobile engine 11 is considered is described. Such malfunctions result in sudden torque changes on the engine side. For this reason the belt tension must be increased in a timely manner.

As possible causes for such a malfunction, the following is considered:

Misfire, ie disturbance in the individual combustion process in the internal combustion engine (11).

A defect in the sensor which outputs an output signal used for the determination of the engine torque M _mot .

-Cylinder cutoff as a result of several types of errors, for example, misfires detected, defective injection valves and defective ignition systems.

-Electrical emergency state of the engine control unit (22).

The probable causes are detected at block 224 of FIG. The block 224 is described in detail using FIG. 5.

To detect misfire (block 2241):

In a modern engine control system, misfire is detected as standard, and at this time the unstable operating value of the engine already mentioned at block 22211 is calculated from the fluctuation of the engine speed N _mot . The unstable operating value dlut of the engine is compared with the threshold Lur adapted at block 22213. If the unstable operating value dlut of the engine exceeds the threshold Lur, misfire is detected and a value Δ1 is formed. The threshold Lur is detected at block 22212 in accordance with engine speed N _mot and air volume Q _L. This can be seen in the prior art mentioned above. The value Δ1 can be fixedly set.

To detect sensor faults (block 2242):

The discussion in this section considers the possibility of a defect in a sensor that outputs an output signal used to determine engine torque M _mot . Therefore, a failure of the air flow meter 24, which may be formed for example as a hot film air flow meter, results in an incorrect torque signal M _mot .

In block 2224 of FIG. 5, monitoring of the engine temperature sensor 33 is shown for this purpose. For this purpose, according to the engine speed N _mot and the air volume Q _L at block 22221, the standard temperature Tm is detected using the stored temperature model and the temperature value T measured at point 22422 is subtracted. . If at block 22423 it is found that the difference exceeds the threshold, then a defect in the temperature sensor 33 can be predicted from it. In this case, a value Δ2 is formed, and this value can be set fixedly.

Other (block 2243):

If the engine control device is in an electrical emergency state or if the cylinder cutoff (cutoff of the fuel supply to the individual cylinders of the automobile engine) is made as a result of several types of errors, a value Δ3 is formed at block 22431, This value can be set statically.

2. Detection of safety reserve as the belt wears or ages (FIG. 7):

As already mentioned, the adjustment of the pressure pushing the belt is optimized between the minimal pressure loss on the one hand and the prevention of belt slip on the other. The pushing pressure required to prevent slip is highly dependent on aging or wear of the belt. In other words, a new belt 1 for transmitting the same engine torque requires less pushing pressure than a belt which is already aged or worn.

In order to take into account the various aging or wear stages of the belt, a constant pressure reserve set in motion can be adjusted. In other words, in the case of a new belt it is possible to drive at an additional pressure that is not necessary.

The key to this part of the present invention is to calculate the aging or wear of the belt and thus to detect the safety reserve for the belt tension.

To do this, via the signal B or switch 1811 to the circuit shown in Fig. 7, a voltage is always applied (position " 1 ") when the vehicle and the transmission operate. In addition, the switch 181 takes the zero voltage position " 0 ". The voltage applied to the block through the integration unit 1814 is integrated to become the aging value AW. First, if the adder 1812 and multiplier 1813 are not considered, the aging value AW first depends only on the operating time of the belt.

However, the aging or wear of the belt 1, in particular the pushing linked bands, is highly dependent on the operating conditions or operating behaviors in which the operation takes place. Several influencing factors are considered by the value offset (adder 1812) and the weight value W (multiplier 1813).

In block 1815 the actual driving situation is assessed in relation to the wear of the belt 1 using situation detection. From this the values (offset and W) are derived. Vehicle dynamics, for example, can be considered in detecting the situation.

The actual engine torque M _mot , transmission temperature T and primary and secondary speeds N _prim , N _sek are provided to the block to form a value (offset and W) at block 1815.

The temperature effect can be taken into account, for example, via transmission temperature T, when forming weighting value W at block 1815. For example, the operating time is considered in the integrating unit 1814 more than the operating time when the transmission temperature and the belt temperature are low when the transmission and belt temperature are large.

This value (offset) is used to account for sudden deterioration or aging. If, for example, belt slip is detected when the speed ratio is the same as the difference between the primary speed (N _prim ) and the secondary speed (N _sek ), local damage or significant aging or considerable wear of the belt 1 occurs. do.

The aging value AW applied to the output of the integration unit is stored in the nonvolatile memory 1815 (EEPROM) and provided to the block 183 (Fig. 8) in operation of the vehicle. Therefore, the storage 1815 is advantageous, so that if the stored value AW is lost, there is no need to switch to a sufficient safety reserve that is dependent on wear as in the prior art.

In such a case, in block 183, according to the aging value AW, a value SR2 for the safety reserve is detected using, for example, a characteristic curve. Aging or wear of the belt is not taken into account when forming the uncorrected belt tension or the uncorrected secondary pushing pressure P _{sek, unk} at block 181. In such a case, the safety reserve SR2 depending on the life or wear is added to the uncorrected value through the adders 188 and 189.

3. Detection of safety reserve according to vehicle dynamics (blocks 185 / Figs. 8 and 10):

When adjusting the pressure to push the belt, in this part of the present embodiment the pushing pressure required to avoid slip is used to find the optimal condition between the minimum pressure loss on one side and the belt slip to be prevented on the other. It is desirable to be influenced by vehicle dynamics. The reason is that driving conditions such as, for example, a significant acceleration, deceleration or skid of the vehicle can cause a sudden torque change (actuated at the transmission output) or torque coupling on the output side at the transmission. Information about such driving conditions may generally be provided to a suitable control device 101 (FIG. 2) or a control device member. The control device is a conventional anti-blocking device (ABS), a drive slip control device (ASR) or a travel stability control device (FDR, ESP), which enhances the driving stability through braking or propulsion interference.

Possible causes for torque coupling by transmission output are:

-Spin of the tire in the driving slip control operation.

Panic braking or strong braking in anti-blocking control actions.

-Vehicle dynamics interference, for example driver-independent and braking interference for each wheel, to prevent skids in the car.

-Go through bad roads.

In the above-mentioned control apparatus 101 (FIG. 2), cases where such torque coupling is made are generally detected or appropriate signals are provided for detection. The signals must be transmitted to the transmission control device 18, where an appropriate response is introduced as increasing the belt tension by the value SR3 or SR4 (block 184, FIG. 8).

The belt tension P _{sek, unk} (target secondary pressure) may be increased through the safety reserve SR4 according to, for example, the braking torque M _br calculated standard in the control device 101. In other words, when the braking torque M _br is increased, the belt tension or the secondary pressure is increased to the set magnitude. This is schematically illustrated in block 184 in FIG. The block is provided with braking torque M _br and safety reserve SR3 is detected using the characteristic curve. The braking torque M _br is transmitted to the transmission control device 18 by, for example, a data line 23 (eg CAN).

The braking torque M _br is generally dependent on the control device 101 as follows:

Braking pressure measured at the brake pedal (driver-dependent braking interference) and

-Rated braking torque during driver-independent braking interference (without brake pedal operation)

The signal (M The advantage of) is that it represents the next braking interference very early. That is, the signal (M ) Shows the braking interference and possible torque jumps at the transmission output prior to actual braking interference (usually the brake hydraulic pressure rise in the brake system) and prior to the actual deceleration of the vehicle. Therefore, the belt tension can be increased in time before the torque fluctuation is coupled by the drive train.

In addition, it can be distinguished in which axis or in which wheel the braking torque M _br appears. Because only dangerous torque coupling to the belt appears on the drive shaft, only the brake interference on the drive shaft should be considered in belt tension.

In a very simple configuration, in the case of brake interference, the pressure P _{sek, unk} that is pushed through the control device 101 is increased by a fixedly set safety reserve SR3.

Clutch is generally provided on the drive train. To avoid blocking of the wheels (antiblocking device-interference), the clutch may be fully or partially open at the time of brake interference or generally in the course of a significant braking process. As a result, the torque to be transmitted by the belt may be limited. In addition, the provided clutch is preferably opened for the direct connection of the converter 12 (see Fig. 1). In a particular embodiment the clutch can only be opened for a certain time until the converter clutch is opened. Reopening after opening of the clutch (es) should be made (controlled) so that an impact does not occur as much as possible in the drive train.

Opening of the clutch may be inconvenient when braking interference to increase driving stability. For this reason, the control device 101 transmits a signal (not shown) to the transmission control device 18, which indicates whether the clutch is allowed to open. Similarly, the control device 101 provides a signal (not shown) to the transmission control device 18, which signal is used to avoid blocking of the wheels (blocking device interference) or too large drive slip. It informs whether it is interference (driving slip control device interference) or driving stability interference (driving stability control device interference).

10, block 185 of FIG. 8 is shown in detail. This embodiment relates to detection of spin of wheels or detection of roads with poor road surfaces.

In the brake control device 101, wheel speeds N _rad of all wheels are used. In the following, the signal of the wheel is considered. This signal N _rad is transmitted to block 185 of the transmission control device 18.

Through evaluation of wheel speed or wheel acceleration, the spin of the wheel causing a torque jump in the drive train is detected. To this end, wheel acceleration a _rad is first detected through differential at block 1851. Wheel acceleration is of course provided directly to the transmission control device 18 by the braking control device 101. At block 1852 a value of wheel acceleration is formed, for example filtering through the PT ₁ -member may also be made. In such case the safety reserve SR4 in block 1853 is determined according to the filtered value of the wheel acceleration, for example by means of a characteristic curve.

Significant changes in wheel speed also occur when roads pass through poor roads, which can be detected through evaluation of wheel acceleration. The value SR4 may also take into account the unfair road.

Another sensor signal can likewise be used to detect roads with poor road surfaces. Therefore, for example, a signal of an acceleration sensor for measuring vehicle acceleration can be used.

For another embodiment, the following can be seen:

Of course, a bit coded signal may also be transmitted to the transmission control device 18 by CAN (eg signal "brake operation" or "brake light switched off" "driving stability control device interference interference", "at least one"). Anti-blocking active in the drive wheel "," requires opening of converter clutch "," recognition of bad roads ", etc.).

If the braking torque M _br is large, additionally the converter clutch or the forward clutch (see Fig. 1) can be opened. The CVT transmission 2 can disconnect the output for at least a short time using the forward clutch (until the converter clutch is closed). In this case, the request for opening the converter clutch is transmitted by the control device 101.

The safety reserve SR4 is dependent on the yaw rate ω 'or lateral acceleration aq of the vehicle, since a high yaw rate or high lateral acceleration can be inferred from possible torque jumps in the drive train.

4. Detection of safety reserve according to the distance control (block 187 / FIG. 8):

As already mentioned above, the inter-vehicle distance control system 102 is known in the prior art for detecting the inter-vehicle distance with the preceding vehicle. If the vehicle distance is too narrow, the system interferes with the automobile brakes independently of the driver. Such interference also causes a sudden torque change (which appears at the transmission output) or torque coupling on the transmission side. For this reason, the interference signal ACC is provided to the transmission control device 18 by the inter-vehicle distance control system 102 in accordance with the present invention when such brake interference occurs. The pushing pressure P _{sek, unk} at block 187 (FIG. 8) is increased by the safety reserve SR6.

5. Detection of safety reserve according to road flatness (block 186 / FIG. 8):

The inter-vehicle distance control system 102 mentioned in the previous section detects the distance to the front vehicle through the radar sensor, which is installed in the front area of the vehicle and has a distance of about 150 meters (the distance between A and B in FIG. 11). . The output signal of the radar sensor is used to detect the characteristics or surface structure of the road in front of the car. In that case a suitable signal FB is formed at the unit 102 and provided to the transmission control device 18. A schematic diagram thereof is shown in FIG.

Therefore, the signal FB represents the characteristic of the road that the car will pass after a while. Via the signal FB, the transmission control device 18 receives information at an early stage whether or not a torque jump due to an unstable road (bad road) is considered at the transmission output side. In such a case, in the simplest case, the appropriate safety reserve SR5 is detected at block 186 where the signal FB representing the surface ridge is compared to the threshold.

So far, the effects of bad roads in each area have been considered through evaluation of engine speed or wheel acceleration. Through the signal FB is much more effective, because to reach, the damage of the belt 1 due to the increase in pushing pressure is suppressed.

12 is a flow diagram of block 186.

After the start step 1001, in step 1002 the road value FB and the motor vehicle dependence V (for example, detected from the wheel speed in the brake control device 101) are read. In step 1003, the road value FB, which represents the road inaccuracy, is compared with the threshold SW. If FB exceeds the value SW, there is a road with bad road surface at distance A-B (step 1004). If there is no road with bad road surface, the process goes to the final step 1008.

If it is detected in step 1004 that the road surface to be run is a bad road, the time from the distance A-B and the vehicle speed V to reach the road area with the bad road surface is detected in step 1005. Then, in step 1006, when the motor vehicle reaches a road area with a bad road surface, the safety reserve SR5 is detected so that the pushing pressure is sufficiently large. SR5 takes a fixed value.                 

If the end of the road area with bad road surface is detected from the signal FB in step 1007, the process advances to the final step 1008.

Preferably, in step 1006, the torque converter lockup clutch may be partially or fully open if the road surface passes a bad road area. This minimizes torque jumps in the drive train.

Early detection of bad road areas provides sufficient time to open the torque converter lockup clutch.

Claims (13)

The gear ratio can be adjusted steplessly and is a device for adjusting the tension of the belt (1) of the continuously variable transmission installed downstream of the automobile engine (11), and controls the first means (22) and the continuously variable transmission for controlling the automobile engine (11). Having a second means 18, a first signal M _mot indicative of the engine torque of the automobile engine is detected via the first means 22, and the first signal M _mot is second from the first means. An apparatus for adjusting the belt tension of a continuously variable transmission, wherein the tension is provided to the means and the tension is adjusted according to the first signal and the safety reserve SR via the second means. A second signal ΔM _mot indicative of the quality of the first signal is detected via the first means 22, and the second signal ΔM _mot is transmitted from the first means 22 to the second means 18. And the safety reserve SR is detected according to a second signal, An aging value (AW) detection means 181 is provided, by means of which the aging value AW detection means 181 is detected an aging value AW indicative of wear or aging of the belt and the safety reserve SR Detected according to the aging value (AW), A third signal M, provided with a third means 101, indicative of braking performance adjusted at the wheel or yawing or transverse motion of the motor vehicle , ω ', aq are detected using the third means 101, and the third signal M , ω ', aq are provided from the third means to the second means 18 and the safety reserve SR is detected according to the third signal, A fourth signal (N _rad , a _rad ) indicative of the speed or change of speed of the at least one wheel is provided to the second means 18, the safety reserve SR is detected in accordance with the fourth signal, A fourth means 102 is provided for distance control, said fourth means 102 detecting an interference signal (ACC) which causes or provides interference to the braking device of the motor vehicle in accordance with the distance detection with the front vehicle; The safety reserve SR is detected according to the interference signal ACC, or A fifth means is provided, said fifth means using at least one sensor to detect a road value FB representing an incombustibility of the road through which the vehicle will pass, and the safety reserve SR according to the road value FB A device for adjusting the belt tension of a continuously variable transmission, characterized in that it is detected. The device of claim 1, wherein the second signal (ΔM _mot ) indicates at least the degree of oscillation of the first signal as a quality. The at least one sensor 24, 32, 33 of claim 1, wherein the second signal ΔM _mot outputs an output signal Q ₁ , 123, 126, which is evaluated for control of the vehicle engine 11. Detected according to the tolerance (ΔTol) of The sensor 24 is used for direct or indirect detection of the amount of air supplied to the vehicle engine 11, The sensor 33 is used to detect a temperature which is evaluated for control of an automobile engine, or The sensor (32) outputs an output signal for use in detecting fuel-air-mixers supplied to an automobile engine and is used for detecting exhaust characteristics of the engine. The method of claim 1, wherein the second signal ΔM _mot is detected according to a malfunction detected during the operation of the vehicle engine 11, and the malfunction ΔFF is detected. If misfire is detected through the detection and evaluation of the engine speed N _mot in one or more cylinders of the automobile engine 11, If a malfunction of the sensor which outputs an output signal evaluated for control of the vehicle engine 11 is detected, If there is an electrical emergency in the first means 22, or An apparatus for adjusting the belt tension of the continuously variable transmission, characterized in that if the fuel supply to the individual cylinders of the motor vehicle 11 is interrupted in response to the detected error. The method of claim 1, wherein the second signal ΔM _mot is detected according to the detected unstable operation of the engine 11. -Mechanical vibration is present in the car's drive train, Whether the fuel supply to the individual cylinders of the engine is interrupted, Whether the first means 22 controls the motor vehicle 11 to suppress vibration in the drive train, Whether there is a transition between different modes of operation of the engine, Whether the presence of a set road quality is detected, or A belt tensioning device of a continuously variable transmission, characterized in that it depends on whether the fuel tank is almost empty. 6. The belt tension of the continuously variable transmission according to claim 5, wherein the second signal ΔM _mot is detected according to a stored adaptation value indicating unstable operation of the vehicle engine, and the adaptation value is stored according to a load or a speed. 7. Device to adjust. The method of claim 1, wherein the second signal ΔM _mot is detected according to the inaccuracy that appears when the first signal is detected. A second signal ΔM _mot is detected according to the speed of the engine, or Adaptation of the friction or loss torque during idling of the engine via the first means 22, and the second signal ΔM _mot is detected depending on whether the adaptation is complete or not Device to adjust. The aging value AW is detected according to an operating period of the belt 1, and the aging value AW is determined during an operating period such as a driver's driving behavior, operating temperature or slip of the belt 1. A device for adjusting the belt tension of a continuously variable transmission, characterized in that it is detected in accordance with existing operating conditions. The device of claim 1, wherein said aging value (AW) is detected by said second means (18) and stored non-volatile. 4. The fourth signal N _rad , a _{rad is} provided from the third means 101 to the second means 18 and the third means 101 is an anti-blocking device or a drive slip control device. Or as a running stability control device, wherein the braking torque acting on the wheel is adjusted to increase running stability. 2. The apparatus of claim 1 wherein at least one clutch is provided in the drive train of the vehicle and the clutch is opened in accordance with the road value (FB) and the detected error type. The method of claim 1, The tension of the belt 1 becomes large if a lower quality first signal M _mot is presented compared to the adjusted tension when a high quality first signal is presented, -When the aging or wear is presented with less aging or abrasion compared to the adjusted tension, the tension of the belt 1 becomes larger, The tension of the belt 1 is increased if the yawing motion or the lateral motion or the braking performance is presented larger than the adjusted tension when the yawing motion or the lateral motion or the braking performance is presented small, The tension of the belt 1 becomes larger if the speed or speed change of the at least one wheel is presented larger than the adjusted tension when the speed or speed change is presented small, The tension of the belt 1 becomes large when there is braking interference caused through the fourth means 102, or -When the road inelasticity is presented to be smaller than the adjusted tension when the road inertia is presented, the safety reserve SR is detected in such a way that the tension of the belt 1 is increased. Adjusting device. According to claim 1, wherein the tension value according to the first signal (M _mot ) is detected, the tension value is modified according to the safety reserve (SR), the tension adjustment is made hydraulically and the tension is at least one pressure value ( P _{sek, kor} ), the pressure value P _{sek, unkor} is detected according to the first signal M _mot , and the pressure value is modified according to the safety reserve SR. Device to adjust the belt tension of the continuously variable transmission.

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